I grip a small plastic box in the palm of my hand. I press down on its metal tab. Click! Immediately, a crisp snapping sound fills the air.

Many zoo keepers use clicker training to shape an animal's behavior.

As part of the Oakland Zoo intern program, we attend weekly classes and behind-the-scenes tours. This week’s class was an “Introduction to Operant Conditioning,” which highlighted how zoo keepers use clicker training to shape animal behavior. The crisp click is a trademark of clicker training, which I learned more about during the intern class.

Much like a college intro to psychology course, the class began by describing experiments done by Pavlov. Pavlov would ring a bell (conditioned stimulus) directly before giving food (unconditioned stimulus) to the dog, which caused the dog to salivate (unconditioned response). Eventually, the dogs would salivate when he rang the bell. We also learned about Throndike’s Law of Effect and how consequences influence how likely a behavior will be repeated. In addition, the class taught us how to distinguish between negative/positive reinforcement and negative/positive punishment. Although using punishment might produce faster results, clicker training is a method of positive reinforcement used to shape an animal’s behavior.

Joseph (left), one of the Nubian goats, participated in this week's intern class demonstration.

To practice the skills learned in the class, we walked out towards the goat and sheep yard to clicker train the goats with zoo keeper Liz. The click, which acts as a marker, is immediately followed by a food treat, which is the reinforcement. This way, the animals know the exact moment for which he or she is being rewarded. Using a technique called “shaping,” Liz worked with us to teach a goat to spin while standing on a short wooden table. First, she would reward the goat for a left head turn and then for a shift in body weight, building up towards a complete spin. Only the domestic animals, like goats, are trained to do tricks; the other zoo animals are only trained to do behaviors that help with animal husbandry tasks or veterinary needs. For example, some of the zoo animals are trained to hold still while getting x-ray, injections or blood drawn.

Photo credit: Lisa Clifton-Bumpass

During this week, three of the other interns and I got the opportunity to work with volunteer Lisa on pig training. After harnessing up the pigs, we practiced commands such as taking a step left, right, forward, backwards or standing still. It was extremely important to mark the behavior with the clicker before moving to drop the food reward. In addition, when feeding the reward, I placed it in a spot that reinforces the behavior. For instance, if I wanted a “back up,” I would not place the food reward so the pig had to take a step forward to eat it.

Zoo keeper Liz training one of the pigs to rest her head on a crate for eye cleaning.

The handler gave each of the commands to the pig through the harness, making sure the commands were clear. Sometimes we would use contrasting commands, like giving a “left step” cue after practicing several “right steps.” Through clicker training, many of the zoo animals do not need to be put under anesthesia or physically restrained for simple procedures, like giving vaccinations, trimming a goat’s hooves or cleaning a pig’s eyes.